The most celebrated history book in the English language has its own famous founding myth:

“It was at Rome, on the 15th of October 1764, as I sat musing amidst the ruins of the Capitol, while the barefooted friars were singing Vespers in the temple of Jupiter, that the idea of writing the decline and fall of the City first started to my mind.”

Edward Gibbon almost certainly contrived this fanciful recollection, but the scholarship that went into his Decline and Fall still stands, like a timeless Roman ruin: majestic, elegant and even sublime. An object of awe, Gibbon’s history unfolds its narrative from the height of the Roman empire to the fall of Byzantium. The six volumes (published between 1776 and 1788) fall into three parts: from the age of Trajan to “the subversion of the western empire” in 395 AD; from the reign of Justinian in the east to the second, Germanic empire, under Charlemagne, in the west; and from the revival of this western empire to the fall of Constantinople in 1453. In so doing, Gibbon traces the intimate and profound connection of the ancient world to his own, more modern time, linking more or less explicitly the age of the Enlightenment to the age of Rome.

Gibbon may have been an amateur historian (his life was otherwise devoted to nurturing his family’s considerable wealth, and to serving in the militia), but his erudition is staggering. It was commonplace in Augustan England of the 18th century to refer to Virgil, Ovid, or Plutarch. Gibbon alludes to passages in Strabo, Sallust, Seneca, Macrobius and Longinus, among many others.

Next to his learning, there’s his style, whose later devotees include both Winston Churchill, (No 43 in this series), and Evelyn Waugh. “It has always been my practice,” wrote Gibbon, “to cast a long paragraph in a single mould, to try it by my ear, to deposit it in my memory; but to suspend the action of the pen till I had given the last polish to my work.”

Decline and Fall is a cathedral of words and opinions: sonorous, awe-inspiring and shadowy, with odd and unexpected corners of wit and irony, concealed in well-judged footnotes. For example, in chapter VII on Gordian, he writes:

Twenty-two acknowledged concubines, and a library of 62,000 volumes attested the variety of his inclinations, and from the productions which he left behind him, it appears that the former as well as the latter were designed for use rather than ostentation.

His footnote provides a witty coda: “By each of his concubines, the younger Gordian left three or four children. His literary productions were by no means contemptible.”

He was also happy to disavow any consequence to this immense undertaking: “History is, indeed, little more than the register of the crimes, follies, and misfortune of mankind.” Gibbon also liked to season his narrative with pithy asides. For example: “Conversation enriches the understanding, but solitude is the school of genius.” And again, in chapter VIII: “All taxes must, at last, fall upon agriculture.” Sometimes, Gibbon is almost the equal of Tacitus in his brutal summaries of the historical process: “Corruption, the most infallible symptom of constitutional liberty.”

And then there’s his intellectual background, as a scholar steeped in the age of reason. Gibbon famously blamed Christianity for the disintegration of the Roman empire:

“As the happiness of a future life is the great object of religion, we may hear without surprise or scandal that the introduction, or at least the abuse, of Christianity had some influence on the decline and fall of the Roman empire. The clergy successfully preached the doctrines of patience and pusillanimity; the active virtues of society were discouraged; and the last remains of military spirit were buried in the cloister: a large portion of public and private wealth was consecrated to the specious demands of charity and devotion; and the soldiers’ pay was lavished on the useless multitudes of both sexes who could only plead the merits of abstinence and chastity. Faith, zeal, curiosity, and more Earthly passions of malice and ambition kindled the flame of theological discord; the church, and even the state, were distracted by religious factions, whose conflicts were sometimes bloody and always implacable; the attention of the emperors was diverted from camps to synods; the Roman world was oppressed by a new species of tyranny; and the persecuted sects became the secret enemies of their country.”

However, here and there, as in his account of Constantine’s conversion, he grudgingly allows for the benefits of religion, too:

“The sacred indolence of the monks was devoutly embraced by a servile and effeminate age; but if superstition had not afforded a decent retreat, the same vices would have tempted the unworthy Romans to desert, from baser motives, the standard of the republic. Religious precepts are easily obeyed which indulge and sanctify the natural inclinations of their votaries; but the pure and genuine influence of Christianity may be traced in its beneficial, though imperfect, effects on the barbarian proselytes of the North. If the decline of the Roman empire was hastened by the conversion of Constantine, his victorious religion broke the violence of the fall, and mollified the ferocious temper of the conquerors.”

After several rewrites, with Gibbon “often tempted to throw away the labours of seven years”, the first volume of his Decline and Fall was published on 17 February 1776, less than six months before the US declaration of independence, a famous climax to the revolution in the American colonies, and a more than passing coincidence. Two months after the first publication of the first volume of this colossal classic, Gibbon boasted to his stepmother about his work’s reception: “It has been very well received, by men of letters, men of the world, and even by fine feathered ladies.”

It is, in other words, a work of universal interest, and timeless influence, unquestionably a magnificent classic of our literature. Gibbon’s own farewell to his masterpiece is almost more affecting than his celebrated account of its genesis:

“It was on the day, or rather the night, of 27 June 1787, between the hours of 11 and 12, that I wrote the last lines of the last page in a summer-house in my garden... I will not dissemble the first emotions of joy on the recovery of my freedom, and perhaps the establishment of my fame. But my pride was soon humbled, and a sober melancholy was spread over my mind by the idea that I had taken my everlasting leave of an old and agreeable companion, and that, whatsoever might be the future date of my history, the life of the historian must be short and precarious.”

A signature sentence

“The strength of the frontiers, which had always consisted in arms rather than fortifications, was insensibly undermined; and the fairest provinces were left exposed to the rapaciousness or ambition of the barbarians, who soon discovered the decline of the Roman empire.”

•The History of the Decline and Fall of the Roman Empire by Edward Gibbon is available from Penguin Classics in three volumes, along with an abridged edition (£12.99). To order the latter for £11.04 go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99